Copper-antimony or copper-bismuth coated ferrous metals



E. C. DOMM COPPER ANTIMONY OR COPPER BISMUTH COATED FERROUS METALS FiledJuly 8, 1955 jzverz 2 07". @272 @776 zrzjam 772,

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corporation oi ilhichiaan application liuly d, i035, denial Nil. timidmyention relates to copper-coated ferrous metals and a method ofpreparing them, and more particularly to rubber-coated ferrous ob-.iects hag coppe'-antimony, copper-arsenic or copper-bismuthundercoatings.

in the production of steel objects, and particularly objects which areto be rubber-coated, it is necessary to secure very great adhesion torubher. it has hitherto been attempted to electro-v plate alloysdirectly upon ferrous objects, but this presents extreme ertculues,inasmuch as it is essential to maintain the current density without theslightest variation. in connection with irregularly shaped articles suchas motor mounts, in which the utmost in aesion'is required, such ormityis not ohtable by this method.

. it has now been discovered that a ferrous ob- ,iect y be plated withcopper, d then y be plated with a thin coating of arsenic timony or boththereon. e neither the copper nor the arsenic antimony or bismuth haveany subs h the copper d time copper d arsenic, and copper and bismuth,when plated separately upon each other, auect each other in some way,presbly by alloying, so that the metals, when rubber is vulcanzedthereon, eive tremendous adherence thereto. Motor mots so treated showan adherence scient to resist a stress of from 300 lbs. to over 000 lbs.per one inch without tearing. As a tter of fact, the timber will oftenbe found to'rupture within itself rather than to p loose fro the etai.

m accordance with the intion, a ferrous object, such as a tor mount l,which is illustrated diaeraatic in-hrohen section in drawing, iselectroplated with a coat of copper f, and a thin cos of arsenic anonyor bismuth t is then plated thereon, after which a rubber coat i is o: 11 ed thereto. The deposition of the metals y be accoplished byelech'oplat, but it is preferred to treat the ferrous object with anacied solution of copper sulfate, whereby copr deposition is secured byionic displacement. a satisfactory solution for this pse may bepreparedin the proportions of a on. copper sulfate, l gallon of water,and flu allon ofm to acid.. The ferrous object is cl t: ed, asby acid,s-poper or sand-blast,

is then dipped into the solution for l-2 secin adherence to rubber bythemselves;

. of the baths (i513. ib-$0.2)

tion of the copper by displacement from a solution of an appropriateelectrolyte. in the case of antimony, a satisfactory electrolyte may beprepared by dissolving t on. of antimony trichloride in a mixture of 2gallons of hydrochloric acid (40%) and 8 gallons ofwater. The article is'ersed in this solution for a period of 1 to 3 seconds and is thengivena cold water rinse. it is then promptly dried to prevent corrosion.Pref- V erably the drying is carried out by ersion for M a few secondsin a hath of boiling yvater, after which air-drying will take placerapidly enough to prevent corrosion.

in the case of bismuth, a satisfactory solution may be prepared in theproportions of 2 oz. of w sodi hisrnuthate, 2 oz. sodium chloride,galion concentrated murlatic acid and 5; gallon of warm water. Thesolution is thoroughly mixed and is then readyfor use. The article maybe ersed from 3-10 seconds, is then treated m as in the case of theantimony-coated article.

In the case of arsenic, it is preferred to plate by substitution ofarsenic for a portion of the copper, by displacement from a solution ofan arsenic electrolyte. it satisfactory solution may be pre- 25 paredfrom 3 on. of sodium cyanide, oz. red

, corrosion.

it has been discovered that the concentration y M11 r Wl. m-1 ratherwide limits without aflec s the rate of deposition of either an, thecopper, antimony or bismuth. For example, the copper content may varyfrom 0 to 16 grams per liter, the arsenic from .i to 45 gram per liter,the antimony from 10 grams to 20 grams per liter, and the bismuth from7.5 to 15 grains- M per liter with no substantial variation in. the rateof deposition. l i ersion of a ferrous article as described will producea uniform copper cos. of .002 to .007" oz. of copper per square foot ofarea, the arsenic will plate a uniform w coat of about .00l to .005ounce per square foot, the antimo bath will plate a uniform coating ofabout .005 0a. of antimony per square footand the bismuth solution be ofthe order of .l or. of bismu Following the plating treatment, theferrous object is coated with rubber which is then vulcanized. In eachcase the use of a copper undercoat produces many times the adherence torubber brought about by the use of the metal without the under-coat.

As used in this application, the term electroplating denotes any form ofcoating by electricity, whereas electrodeposition is used to denoteionic displacement. The rubber used for the coating material may be anysuitable form of 1111)- ber, and these are well known to those skilledin the art.

The foregoing detailed description has been given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, but the appended claims should be construed as broadly aspermissible, in view of the prior art,

This application is a continuation in part of my copending applicationSer. No. 706,736 filed J anuary 15, 1934.

What I claim as new, and desire to secure by Letters Patent, is:

1. The method of producing a highly rubber adherent ferrous base objectwhich comprises plating a thin layer of substantially pure copperthereon, and electroplating a layer of metal of the class consisting ofarsenic, antimony and hismuth thereon, the layer being thin enough toalloy throughout with the copper under atmospheric temperature or thetemperature of vulcanization, and adherently vulcanizing a coating ofrubber thereto.

2. The method as set forth in claim 1, in which the second metal isarsenic.

3. The method as set forth in claim 1, in which the second metal isbismuth.

4. The method as set forth in claim 1, in which the second metal isantimony.

5. The method as set forth in claim 1, in which the thickness of thecopper is of the order of .002 to .007 ounce per square foot of area.

6. The method as set forth in claim 1, in which the thickness of thearsenic antimony or bismuth is of the order of .001 to .005 ounce persquare foot of surface.

7. The method as set forth in claim 1, in which the thickness of thecopper is of the order of .002 to .007, and of the arsenic, antimony orbismuth is of the order of .001 to .005 ounce per square foot of area.

8. The method of claim 1, in which the double plated object, while stillwet, is immersed in hot water, whereby it is rapidly dried without cor-9. A ferrous highly rubber adherent base object comprising a ferrousbase, a thin substantially pure copper layer thereon, a layer of metalof the class consisting of arsenic, antimony and bismuth on the copper,the layer being thin enough to alloy throughout with the copper underatmospheric temperature or the temperature of vulcanization, and a layerof rubber adherently vulcanized thereto.

10. A ferrous base object as in claim 9, in which the second metal isarsenic.

11. A ferrous base object as in claim 9, in which the second metal isantimony.

12. A ferrous base object as in claim 9, in which the second metal isbismuth.

13. An object as in claim 9, in which the object is a steel motor mount,and in which the thickness of the arsenic antimony or bismuth layer isof the order of .001 to .005 ounce per square foot of area.

14. An article as set forth in claim 9, in which the thickness of copperis of the order of .002 to .00! ounce per square foot of area.

15. An article as set' forth in claim 9, in which the thickness of thearsenic antimony or bismuth is of the order of .001 to .005 ounce persquare foot of surface. r

16. An article as set forth in claim 9, in which the thickness of thecopper is of the order of .002 to .007 and of the arsenic antimony orhismuth is of the order of .001 to .005 ounce per squarefoot of area.

17 The method of producing a highly rubber adherent ferrous base objectwhich comprises electroplating a thin layer of substantially pure copperthereon, and electrodepositing a layer of metal of the class consistingof arsenic, antimony and bismuth thereon, the layer being thin enough toalloy throughout with the copper under atmospheric temperature or thetemperature of vulcanization, and adherently vulcanizing a coating ofrubber thereto.

18. The method of producing a highly rubber adherent ferrous base objectwhich comprises electrodepositing a thin layer of substantially purecopper thereon, and electrodepositing a layer of metal of the classconsisting of arsenic, antimony and bismuth thereon, the layer beingthin enough to alloy throughout with the copper under atmospherictemperature or the temperature of vulcanization, and adherentlyvulcanizing a coating of rubber thereto.

19. The method of producing a highly rubber adherent ferrous base objectwhich comprises electrodepositing a thin layer of substantially purecopper thereon, and electrodepositing a layer of metal of the classconsisting of arsenic, antimony and bismuth thereon, the layer beingthin enough toalloy throughout with the copper under atmospherictemperature or the temperature of vulcanization.

20. A ferrous base object comprising a ferrous base, a thinsubstantially pure copper layer thereon, a layer of metal of the classconsisting of arsenic, antimony and bismuth on the copper, the layerbeing thin enough to alloy throughout with the copper under atmospherictemperature.

ELGIN CARLETON DOMM.

